package com.atguigu.gulimall.product.service.impl;

import com.atguigu.gulimall.product.service.CategoryBrandRelationService;
import com.atguigu.gulimall.product.vo.Catelog2Vo;
import org.checkerframework.checker.units.qual.C;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.atguigu.common.utils.PageUtils;
import com.atguigu.common.utils.Query;

import com.atguigu.gulimall.product.dao.CategoryDao;
import com.atguigu.gulimall.product.entity.CategoryEntity;
import com.atguigu.gulimall.product.service.CategoryService;
import org.springframework.transaction.annotation.Transactional;


@Service("categoryService")
public class CategoryServiceImpl extends ServiceImpl<CategoryDao, CategoryEntity> implements CategoryService {

    @Autowired
    CategoryBrandRelationService categoryBrandRelationService;

    @Override
    public PageUtils queryPage(Map<String, Object> params) {
        IPage<CategoryEntity> page = this.page(
                new Query<CategoryEntity>().getPage(params),
                new QueryWrapper<CategoryEntity>()
        );

        return new PageUtils(page);
    }

    /**
     * 查出所有分类及子分类，以树形结构组装起来
     */
    @Override
    public List<CategoryEntity> listWithTree() {
        //1、查出所有分类
        List<CategoryEntity> entities = baseMapper.selectList(null);
        //2、组装成父子的树形结构
        //2.1)、找到所有的一级分类
        List<CategoryEntity> level1Menus = entities.stream().filter((categoryEntity) -> {
            return categoryEntity.getParentCid() == 0;
        }).map((menu) ->{
            menu.setChildren(getChildren(menu,entities));
            return menu;
        }).sorted((menu1, menu2) -> {
            return (menu1.getSort() == null ? 0 : menu1.getSort()) - (menu2.getSort() == null ? 0 : menu2.getSort());
        }).collect(Collectors.toList());
        return level1Menus;
    }

    @Override
    public void removeMenuByIds(List<Long> list) {
        //TODO 1、检查当前删除的菜单，是否被其他地方引用

        //逻辑删除
        baseMapper.deleteBatchIds(list);
    }

    @Override
    public Long[] findCatelogPath(Long catelogId) {
        List<Long> paths = new ArrayList<>();
        List<Long> parentPath = findParentPath(catelogId, paths);
        Collections.reverse(parentPath);
        return parentPath.toArray(new Long[parentPath.size()]);
    }

    /**
     * 级联更新所有关联的数据
     * @param category
     */
    @Transactional
    @Override
    public void updateCascade(CategoryEntity category) {
        this.updateById(category);
        categoryBrandRelationService.updateCategory(category.getCatId(),category.getName());
    }

    @Override
    public List<CategoryEntity> getLevel1Categories() {
        List<CategoryEntity> entities = baseMapper.selectList(new QueryWrapper<CategoryEntity>().eq("parent_cid", 0));
        return entities;

    }

    @Override
    public Map<String, List<Catelog2Vo>> getCatalogJson() {

        // 1. 查询所有一级分类
        List<CategoryEntity> level1Categories = getLevel1Categories();

        // 2. 构建分类树形结构
        return level1Categories.stream().collect(Collectors.toMap(
                level1 -> level1.getCatId().toString(),
                level1 -> {
                    // 2.1 查询二级分类
                    List<CategoryEntity> level2Categories = baseMapper.selectList(
                            new QueryWrapper<CategoryEntity>().eq("parent_cid", level1.getCatId()));

                    return level2Categories.stream().map(level2 -> {
                        // 2.2 构建二级分类VO
                        Catelog2Vo catelog2Vo = new Catelog2Vo(
                                level1.getCatId().toString(),
                                null,
                                level2.getCatId().toString(),
                                level2.getName());

                        // 2.3 查询三级分类
                        List<CategoryEntity> level3Categories = baseMapper.selectList(
                                new QueryWrapper<CategoryEntity>().eq("parent_cid", level2.getCatId()));

                        if (!level3Categories.isEmpty()) {
                            List<Catelog2Vo.Catelog3Vo> level3Vos = level3Categories.stream()
                                    .map(level3 -> new Catelog2Vo.Catelog3Vo(
                                            level2.getCatId().toString(),
                                            level3.getCatId().toString(),
                                            level3.getName()))
                                    .collect(Collectors.toList());
                            catelog2Vo.setCatalog3List(level3Vos);
                        }

                        return catelog2Vo;
                    }).collect(Collectors.toList());
                }
        ));
    }

    private List<Long> findParentPath(Long catelogId, List<Long> paths) {
        //1、收集当前节点id
        paths.add(catelogId);
        CategoryEntity byId = this.getById(catelogId);
        if (byId.getParentCid() != 0) {
            findParentPath(byId.getParentCid(),paths);
       }
        return paths;
    }

    //递归查找所有菜单的子菜单
    private List<CategoryEntity> getChildren(CategoryEntity root, List<CategoryEntity> all) {
        List<CategoryEntity> children = all.stream().filter(categoryEntity -> {
          return categoryEntity.getParentCid() == root.getCatId();
        }).map(categoryEntity -> {
            //1、找到子菜单
            categoryEntity.setChildren(getChildren(categoryEntity,all));
            return categoryEntity;
        }).sorted((menu1, menu2) -> {
            //2、菜单的排序
            return (menu1.getSort() == null ? 0 : menu1.getSort()) - (menu2.getSort() == null ? 0 : menu2.getSort());
        }).collect(Collectors.toList());
        return children;
    }

}